I just finished watching all 16 episodes. I'm absolutely mind blown by the story telling and the truest portrayal of the characters by the main leads. They have done an absolutely amazing job in engrossing us entirely in the characters. There was so much of attention to detail in portaying subtle emotions that I forgot I was watching a drama in a foreign language I don't understand.
Although the ending is usually not what I hope to see, I'm sure I would be re-watching this drama again just for the main leads.